A flexible redundancy technique for high-density DRAMs

The limitations of conventional redundancy techniques are pointed out and a novel redundancy technique is proposed for high-density DRAMs using multidivided data-line structures. The proposed technique features a flexible relationship between spare lines and spare decoders, as well as lower probability of unsuccessful repair. With this technique the yield improvement factor of 64-Mb DRAMs and beyond is estimated to be more than twice that with the conventional technique in the early stages of production